Autoballistic antenna



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J. W. IRBY AUT'o-BALLISTIC ANTENNA Filed April 30, 1943 MNA?? (rl, f

Patented Feb. 14, 1950 UNITED STATES PATENT OFFICE AUTOBALLISTIC ANTENNA James W. Irby, Dayton, Ohio Application April 30, 1943, Serial No. 485,101 4 claims. (o1. 25o-33) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to improvements in antenna for radio apparatus.

In certain military operations it is necessary to provide a device for extending a normally collapsed antenna for use in installations where radio apparatus is to be operated at a predetermined time and the antenna must be erected automatically without requiring the presence of an operator. Such an antenna, when not in use, should occupy a minimum of space so that it can be easily transported and not be exposed to the possibility of damage as would be the case with an extended antenna.

It is, therefore, an object of this invention to provide a normally collapsed antenna which can be instantly extended automatically when desired.

A further object is the provision of an extensible antenna in which all parts have tight electrical connection when the antenna is extended.

A further object is the provision of an extensible antenna which is instantaneous in operation, positive in action, light in weight and not affected by changes in temperature or climatic conditions.

These and other objects are attained by the novel structure and arrangement of parts hereinafter described and illustrated in the accompanying drawings, forming a part hereof, and in which:

Fig. lis a perspective view of an extensible antenna embodying the invention.

Fig. 2 is a sectional View of the antenna in extended condition.

Fig. 3 is a perspective view, partially in section, of a tight fitting joint between two telescoping members adapted to be employed in the device.

Referring to Figs. 1 and 2 of the drawings, the extensible antenna is shown to comprise a plurality of telescoping antenna members I, 2, 3, and 4. The members I, 2, 3, have one end thereof flared at 5, 6, respectively to provide stops adapted to tightly engage shoulders 8, 9, I0, formed respectively on members 2, 3, 4 and provide good electrical contact between the several members. The upper end of member I is closed. A plug or adapter I| is threaded into the lower end of member 4 and has a passage I2 drilled therethrough, which has a restricted portion I3 communicating with a right angularly directed passage I4 drilled in an extension I5 of the plug.

The plug II is also in threaded engagement with one end of a hollow casing I6, preferably made of steel, and forming an explosion chamber. A block 'I closes one end of the chamber and is provided with a longitudinal orifice I8 adapted to receive a cartridge I9 of gunpowder or other explosive.

A back plate 2|) is secured to the block I1 by screws 2|, and has a central aperture through which a ring pin 22 can move to strike the cartridge I9. To insert the cartridge I9, Yscrews 2| and back plate 2|] are removed and cartridge I9 is inserted into orice I8 in block I'I.

Supported by plate 20 is a tube 23 in which is slidably mounted a bolt 24 having at one end thereof a ange 25 which engages one end of a compression spring 2B, the other end of the spring engaging the end 28 of the tube 23. When the antenna is in a collapsed condition the bolt is held in a retracted position, (see Fig. l), against the pressure of the spring 26, by means of a pin 21.

In operation, the extensible antenna is mounted in a collapsed condition at some point which would be inaccessible or dangerous to an operator at the predetermined time set for extending the antenna.

The pin 21 would have a wire or cord tied thereto, and at the predetermined time, the pin can be withdrawn by an operator at a remote and safe point to release the bolt 24 to allow the bolt to be forced by the compression spring 26 to strike the firing pin 22 and explode the cartridge of gunpowder. The expanding gases resulting from the explosion pass through restricted passages I4, I3 into passage I2 and instantly force antenna member I to an extended position. The restricted passages convert the explosive force into a more or less smoothly applied pressure, and thus prevent damage to the telescopic elements. As member I moves outwardly, it tightly engages member 2, carrying member 2 with it. Member 2 in turn engages member 3, which in turn engages member 4 to cause the antenna to be completely extended with all members having good and tight electrical contact with each other.

From the above description it will be seen that there has been provided a simple and effective antenna device which occupies small space when collapsed and not in use, and which can be instantly extended automatically by an operator from a remote point.

In Fig. 3 is shown another arrangement for providing tight connections between the telescoping antenna members when extended. In this form, for example, a tubular member 30 is telescoped within a larger tubular member 3|, which is provided at one end thereof with an internally tapered sleeve 32. The member 30 is provided with an externally tapered sleeve 33 coated with a sheet 34 of soft metal. When the members are extended, the sleeves 32 and 33 will have Wedging engagement, thus producing a tight locking connection. The wedging eiiect is increased by the engagement o f the soft metal sheet 34 with the hard metal sleeve 32, While only two antenna members are shown in Fig. 3, it is understood that similar tapered sleeves are provided for other adjacent members of the antenna.

The above description is to be regarded as il: lustrative only and not limitative of the invention, of which obviously modifications can be made without departing from the spirit of the invention as set forth in the appended claims.

Having described the invention what is claimed 1. An extensible antenna for radio apparatus, comprising a chamber having a constant volume and holding explosive material, a plurality of tubular telescoping antenna members forming an enclosed extensible chamber communicating with the rst mentioned chamber, means to fire the explosive, means to apply the explosive pressure to the innermost telescoped member to force said member to an extended condition, means carried by the inner telescoped members for carrying the outer telescoped members to an extended condition and wedging means between adjacent antenna members to provide tight connections between the members when extended.

2. In an extensible antenna for radio apparatus,

a plurality of telescoped antenna members, and

cooperating tapered sleeves on adjacent members one of the tapered sleeves of each pair of adjacent members being coated with soit metal, the other sleeve being formed of a relatively hard metal to tightly wedge and lock the members together when forced to a fully extended condition.

3. An extensible antenna for radio apparatus, comprising a chamber having a constant volume and holding explosive material, a plurality of tubular telescoping antenna members forming an enclosed extensible chamber communicating with the iirst mentioned chamber, means to explode said material whereby the innermost telescoped member is forced to an extended position, means carried by said innermost member for carrying the outer telescoped members to an extended position and means to tightly lock adjacent members together when extended. 4. An extensible antenna for radio apparatus comprising an exlosion chamber having a constant volume, a plurality oftubular telescoping 4 antenna members forming an enclosed extensible chamber, said enclosed extensible chamber being xed to one end of said explosion chamber by means of an adapter, said adapter providing a restricted passage between said explosion chamber and said lenclosed extensible chamber, cooperating tapered sleeves on adjacent telescoping members to tightly wedge and lock the members together when they are in a fully extended position, one of the tapered sleeves of each pair of adjacent members being coated with soft metal, the other tapered sleeve complementary therewith being formed of a relatively hard metal; a longitudinally bored block fixed to the other end oi said explosion chamber, a cartridge iixedly positioned within said bore, a plate xed to the free end of said block and provided with a longitudinal bore of lesser diameter than the bore in said block and in register therewith, a firing pin having a cartridge striking shank complementary in diameter to the bore in said plate and having a head greater in diameter than said shank, a tubular element longitudinally aligned with said explosion chamber and With said enclosed extensible chamber and having an inner diameter greater than the diameter of said firing pin head, said tubular element being afxed to said plate, a bolt slidably positionable within said tubular element, and means to hold said bolt in a normally withdrawn position, said means comprising a compression spring axially carried by said bolt and a pin transversely insertable into said tubular element and cooperating with said spring to release said bolt and move said iiring pin shank against said cartridge, whereby said cartridge may be exploded and gas may be generated to pass through said restricter passage and gradually move said telescoping members into an extended position.

JAMES W. IRBY.

REFERENCES CITED The following references are of record in the nie of this patent:

UNITED STATES PA In.' NTS Number Name Date 1,318,954 Barlow Oct. 14, 1919 1,320,659 Thornycroit Nov. 4, 1919 1,672,596 Zerk June 5, 1928 1,985,184 Methlin Dec. 18, 1934 2,172,117 Beaufort et al.y Sept. 5, 1939 2,198,697 Driggs Apr. 30, 1940 2,239,614 Martin Apr. 22, 1941 2,286,764 Scott-Paine June 16, 1942 2,300,847 Russel Nov. 3, 1942 

